Repository: hbase Updated Branches: refs/heads/master 555469287 -> a86d4dbfe
HBASE-10950 Document global configuration for maxVersion Project: http://git-wip-us.apache.org/repos/asf/hbase/repo Commit: http://git-wip-us.apache.org/repos/asf/hbase/commit/a86d4dbf Tree: http://git-wip-us.apache.org/repos/asf/hbase/tree/a86d4dbf Diff: http://git-wip-us.apache.org/repos/asf/hbase/diff/a86d4dbf Branch: refs/heads/master Commit: a86d4dbfe9030346fef2aefceec1de7420bceba2 Parents: 5554692 Author: Misty Stanley-Jones <mstanleyjo...@cloudera.com> Authored: Tue Sep 16 13:02:21 2014 +1000 Committer: Misty Stanley-Jones <mstanleyjo...@cloudera.com> Committed: Tue Sep 16 13:02:21 2014 +1000 ---------------------------------------------------------------------- src/main/docbkx/book.xml | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/hbase/blob/a86d4dbf/src/main/docbkx/book.xml ---------------------------------------------------------------------- diff --git a/src/main/docbkx/book.xml b/src/main/docbkx/book.xml index 00c5041..01c6b41 100644 --- a/src/main/docbkx/book.xml +++ b/src/main/docbkx/book.xml @@ -660,6 +660,37 @@ try { <emphasis>Overwriting values at existing timestamps</emphasis> mentioned in the article no longer holds in HBase. This section is basically a synopsis of this article by Bruno Dumon.</para> + + <section xml:id="specify.number.of.versions"> + <title>Specifying the Number of Versions to Store</title> + <para>The maximum number of versions to store for a given column is part of the column + schema and is specified at table creation, or via an <command>alter</command> command, via + <code>HColumnDescriptor.DEFAULT_VERSIONS</code>. Prior to HBase 0.96, the default number + of versions kept was <literal>3</literal>, but in 0.96 and newer has been changed to + <literal>1</literal>.</para> + <example> + <title>Modify the Maximum Number of Versions for a Column</title> + <para>This example uses HBase Shell to keep a maximum of 5 versions of column + <code>f1</code>. You could also use <link + xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html"; + >HColumnDescriptor</link>.</para> + <screen><![CDATA[hbase> alter ât1â², NAME => âf1â², VERSIONS => 5]]></screen> + </example> + <example> + <title>Modify the Minimum Number of Versions for a Column</title> + <para>You can also specify the minimum number of versions to store. By default, this is + set to 0, which means the feature is disabled. The following example sets the minimum + number of versions on field <code>f1</code> to <literal>2</literal>, via HBase Shell. + You could also use <link + xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html"; + >HColumnDescriptor</link>.</para> + <screen><![CDATA[hbase> alter ât1â², NAME => âf1â², MIN_VERSIONS => 2]]></screen> + </example> + <para>Starting with HBase 0.98.2, you can specify a global default for the maximum number of + versions kept for all newly-created columns, by setting + <option>hbase.column.max.version</option> in <filename>hbase-site.xml</filename>. See + <xref linkend="hbase.column.max.version"/>.</para> + </section> <section xml:id="versions.ops">
